Wrapping machine



Sept. 20, 1966 D. E. BURT 3,273,307

WRAPPING MACHINE 7 Filed Aug. 5, 1964 11 Sheets-Sheet 1 INVENTOR DomZdEBurt ATTORNEYS Sept. 20, 1966 n. E. BURT WRAPPING MACHINE 11 Sheets-Sheet 2 Filed Aug. 3, 1964 Domldli'. B ZUZ Sept. 20, 1966 n. E. BURT WRAPPING MACHINE \Q was Flled Aug 3 1964 Sept. 20, 1966 D. E. BURT 3,273,307

WRAPPING MACHINE Filed Aug. 3, 1964 ll Sheets-Sheet 4 INVENTOR Sept. 20, 1966 D. E. BURT 3,273,307

WRAPPING MACHINE Filed Aug. 5. 1964 11 Sheets-Sheet s DomZdEBwq Sept. 20, 1966 D. E. BURT 3,273,307

WRAPPING MACHINE Filed Aug. 3, 1964 11 Sheets-Sheet 6 Donald EBurfi Sept. 20, 1966 D. E. BURT WRAPPING MACHINE 11 Sheets-Sheet 7 Filed Aug. 5, 1964 Sept. 20, 1966 n. E. BURT WRAPPING MACHINE 11 Sheets-Sheet 8 Filed Aug. 3, 1964 m 6 6 m 4 w 6 w o 2 2 I .l. 6 o J p Jo7//%/////f///////////// N 6 HM! H i I W k g I m o W Z w m m INVENTOR Do ncrZoZEBuri Sept. 20, 1966 D. E. BURT WRAPPING MACHINE 11 Sheets-Sheet 9 Filed Aug. 5, 1964 INVENTOR D0 nczZcZZZTB 10 ATTORNEYS Sept. 20, 1966 D. E. BURT 3,273,307

WRAPPING MACHINE Filed Aug. 5, 1964 11 Sheets-Sheet 10 INVEN'IOR flonacldli'. Burt ATTORNEYS Sept 1966 D. E. BURT 3,273,307

WRAPPING MACHINE Filed Aug. 3, 1964 11 Sheets-Sheet 11 )i. 3' 366 %;T 3 I? 520 320 -ln I l 'vg /fi 3436 o A 0 I DomldfifBur'l ATTORNEY 5 United States Patent 3,273,367 WRAPPING MACHINE Donald E. Burt, Boston, Mass., assignor to Keyes Fibre Company, Waterville, Maine, a corporation of Maine Filed Aug. 3, 1964, Ser. No. 386,822 21 Claims. (Cl. 53-228) This invention relates to wrapping machines, and more particularly to a commercial machine for enclosing a wide range of articles in wrapping material and sealing edges thereof to provide merchandizing packages on a high volume mass production basis.

Prior to the present invention, a large number of Wrapping machines for forming many varieties of finished packages have been provided, many of which form particular packages in a highly satisfactory manner. Nevertheless, such machines frequently lack sufficient adaptability for wrapping articles of varying width, height and length dimensions on a given production line with the facility required for high volume operations. For instance, in large produce packaging rooms, trays or boxes made of materials such as molded pulp are packed with fruit, vegetables, berries and the like, and such packed articles are thereafter wrapped with flexible and frequently transparent film. After wrapping, the film may be heat shrunk to provide compact and sturdy merchandizing units ready for shipment to retail distributors. As can be appreciated, such produce packaging rooms handle a large variety of products with a proportionately large variety of containers therefor, and the machine which wraps such filled containers with flexible wrapping material must be quickly adaptable by unskilled labor to accommodate this large variety of packages.

Accordingly, it is an object of the present invention to provide a wrapping machine adaptable to accommodate a large variety of articles having various width, length and height dimensions.

Another object of the present invention is to provide a wrapping machine having a novel conveyor arrangement for transporting articles to be wrapped with a step-by-step motion.

Another object of the present invention is to provide a wrapping machine having a novel arrangement for feeding flexible wrapping material to a wrapping station in an intermittent fashion controlled by the presence and movement of articles to be wrapped.

Another object of the present invention is to provide a wrapping machine having means for simultaneously sealing together plural sheets of thermoplastic material and severing the sealed sheets at the zone where they are sealed to provide two groups of plural sheets sealed at their edges.

Another object of the present invention is to provide a wrapping machine in combination with a heat shrinking arrangement to form wrapped articles into merchandizing packages.

Other objects and advantages of the present invention will become apparent to one skilled in the art from a reading of the following description in conjunction with the accompanying drawings wherein similar reference characters refer to similar parts and in which:

FIG. 1 is a side elevational view of a preferred variety of production line including the machine of this invention;

FIG. 2 is a side elevational view on a larger scale of the machine of this invention;

FIG. 3 is a top plan view of the machine;

FIG. 4 is a front elevational view of the machine;

FIG. 5 is a rear elevational view of the machine;

FIG. 6 is a longitudinal sectional elevational view on line 6-6 of FIG. 3;

FIG. 7 is a fragmentary sectional elevational view on line 7--7 of FIG. 3;

FIG. 8 is a fragmentary sectional view on line 88 of FIG. 7;

FIG. 9 is a plan view with parts broken away showing details of one of the conveyor units;

FIG. 10 is a side elevational view with parts broken away showing detials of one of the conveyor units;

FIG. 11 is a fragmentary detail view of the stop bar and its associated trigger finger;

FIG. 12 is a plan view of the stop bar and its associated trigger finger;

FIG. 13 is a fragmentary detail view of the product sen-sing trip device;

FIG. 14 is a plan view of the product sensing trip device;

FIG. 15 is a fragmentary sectional elevational view of the upper film unrolling apparatus and associated printing arrangement;

FIG. 16 is a sectional view illustrating details of upper and lower sealing bars in a partly closed position; and

FIG. 17 is a sectional view illustrating details of upper and lower sealing bars in the fully closed position.

Referring more particularly to the drawings, the wrapping machine 10 of this invention is illustrated in FIG. 1 disposed in a production line for wrapping trays of produce with flexible wrapping material. A first conveyor 12 receives dish-shaped trays 14 or boxes made of material such as molded pulp one at a time from an ar ticle dispensing unit 16, the details of which form no part of the present invention. The trays 14 dispensed from the unit 16 are conveyed in spaced relation toward the wrapping machine 10 past a series of produce loading stations 18. Each such station 18 may comprise machinery for automatically filling the trays 14 with produce or, as illustrated, may simply comprise bins of produce such as oranges or other fruit positioned adjacent the conveyor 12 to facilitate manual loading of the trays 14. The loaded trays 14 are then transported by the conveyor 12 to the front end of the wrapping machine 10 where a covering of wrapping material such as transparent thermoplastic film is combined with the trays to form an enclosed package, as explained in full detail below. Thereafter, a second conveyor 20 may transport wrapped articles away from the rear end of the wrapping machine 10, and through a heating chamber 22 for the purpose of heat shrinking the wrapping film around the fruit in the tray 14 to provide a compact and study merchandizing unit. Finally, an automatic tray stacking and case loading station may be provided to prepare the wrapped merchandizing packages for shipment.

The machine 10 in more detail comprises a main frame 24 defining a front or entrance end 26 and a rear or exit end 28. Additionally, the main frame 24 defines an upper r-oll support arrangement 30 for wrapping material and a lower roll support arrangement 32 for wrapping material, as well as a transverse sealing arrangement 34 and a pair of opposed longitudinal sealing arrangements 36 and 38. Finally, the main frame 24 provides a support for conveyor means 40 which transports articles to be wrapped along a predetermined horizontal path through the machine 10.

The conveyor means 40 comprises a first belt conveyor 42, a second belt conveyor 44 and a third belt conveyor 46 axially aligned longitudinally of the machine 10. Each belt conveyor in turn comprises a series of individual conveyor belt units individutlly mounted on common drive shafts 48, 50 and 52, respectively, which extend transversely of the machine 10. As illustrated in detail in FIGS. 9 and 10, each individual belt conveyor unit comprises a longitudinally extending support or frame 54 having a smooth belt supporting upper surface 56 secured as at 58 thereto. The ends of the support 54 are designed to pivotally mount toothed pulleys 60 and 62. The toothed pulley 60 is a drive pulley having an axially extending split collar 64 which may be tightened against one of the drive shafts by means of a split clamp collar 66 to provide a driving connection between the pulley 60 and drive shaft. The idler pulley 62 is mounted between thrust bearing washers 68 upon a sleeve bearing 70 surrounding a pintal 72 which in turn supports, by a pin 74, a U shaped bracket 76 having lower bifurcated leg portions 78 adapted to straddle a support bar 80 fixed to the frame 24 transversely of the machine. A lock screw arrangement 82 on the bracket 76 is adapted to secure the bracket in fixed relation to the support bar 80 to properly position each conveyor unit. A belt 84 is trained around the pulleys 60 and 62 in the conventional fashion. By loosening the clamp yoke 66 around the drive shaft as well as loosening the locking screw 82 at the other end of each conveyor unit, it will be clear that each conveyor unit may be shifted individually along the drive shaft laterally of the machine to position the plural conveyor units of each belt conveyor to engage particular trays or other articles in the machine to best advantage. In the preferrred embodiment, there are four individual conveyor units comprising each of the three belt conveyors 42, 44 and 46. Additionally, it will be noted that one or more of each of the individual conveyor units may be released from the supporting cross bar 80 and swung about its drive shaft in a vertical plane away from the predetermined horizontal path which articles to be wrapped will follow through the machine if such conveyor unit is not needed, such as when very narrow articles are being wrapped.

Each of the belt conveyors 42, 44 and 46 are driven from a common power source such as an electric motor 86 operating through a-speed reducing gear unit 88 to drive an adjustable power sheave 90. A V belt 92 transmits rotary motion from the sheave 90 to rotate a primary drive shaft 96 by means of an adjustable sheave 94. The drive shaft 96 in turn, as best seen in FIG. 3, rotates a pair of primary drive sprockets 98 about which roller type link chains 100, 102 are trained. The drive chain 100 rotates a sprocket 104 connected with the input shaft of a clutch arrangement 106, the output shaft of which rotates a sprocket 108, which in turn is connected by a roller link chain 110 to a driven sprocket 112 connected to rotate the drive shaft 48 for the belt 42. The opposite end of the drive shaft 48 further may include a brake arrangement 114 for a purpose described below.

The other primary drive sprocket 98 on the primary drive shaft 96 imparts rotary motion via the chain 102 to the input shaft of a clutch arrangement 116 by means of a sprocket 118. The sprocket 118 is also connected for concurrent rotary motion with a sprocket 120 which drives a roller link chain 122. The output shaft of the clutch arrangement 116 is connected to drive a sprocket 124 which by means of a suitable roller link chain 126 drives a sprocket 128 connected to rotate the drive shaft 50 of the second belt conveyor 44. The opposite end of the drive drive shaft 50 also may include a brake arrangement 130 for a purpose described below.

The roller link chain 122 is trained about and drives a sprocket 132 connected with the input shaft of a clutch arrangement 134, the output shaft of which is connected to rotate the drive shaft 52 of the third belt conveyor 46 by means of a suitable chain and sprocket combination 136. The opposite end of the drive shaft 52 also may include a brake arrangement 138 for a purpose described below.

The above described clutch and brake arrangements are connected to be operated by articles to be wrapped as such articles pass along a predetermined path through the machine. Suitable limit switches, trip devices and trigger arrangements described below are interlocked by electric circuitry which per se forms no part of the present invention, and the description of the invention will not be burdened with such details, because it will be apparent to one skilled in the machinery construction arts how the machine may be wired after a careful reading of the following description.

Associated with each of the three belt conveyors is a control device actuated by the articles to be wrapped. The first belt conveyor 42 and the third belt conveyor 46 may include trip devices 140. The two trip devices 140 are similar in construction, and a detailed description of one with reference to FIGS. 13 and 14 will serve as a description of both. Each may be mounted on cross bar support arrangements 142 connected with the main framework 24 of the machine so that the upstanding trip portion 144 thereof extends upwardly between the individual belt units of the first and third belt conveyors. The trip portion 144 is pivotally mounted at 146 relative to the main housing 148 of the trip device. A pair of pivoted links 150 and 152 are biased by-a tension spring 154 secured as at 156 to the housing 148 to position the trip portion 144 in the upward position. An abutment 158 pivoted on a fixed shaft 160 is designed to engage the operating arm 162 of a limit switch 164 when an article to be wrapped engages the trip portion 144 and pivots it downwardly about its pivot 146. As articles pass beyond the depressed trip portion 144, the tension spring 154 serves to return it to its upstanding operative position with a consequent disengagement of the operating portion 162 with the limit switch 164.

The second belt unit 44 may include a stop bar 166 having an associated trigger finger arrangement 168. These members are part of a stop bar unit 170 which may be supported in a longitudinal slideway 172 by means of laterally outwardly flanged portions 174 on the base of the unit 170. The longitudinal slideway 172 is supported on a floor portion 176 extending across the mid-portion of the machine 10.

As best seen in FIGS. 11 and 12, the unit 170 includes a limit switch 176 having a pivotally arranged operating arm 17 8, as well as a fluid motor 180 the cylinder 182 of which is secured thereto. An upstanding guide member 184 having a guide roller 186 pivoted at the upper end thereof is designed to support for vertical sliding motion the hollow stop bar 166 and its associated trigger finger arrangement 168. The lower portion of the stop bar 166 is connected by a laterally extending portion 188 with the piston rod 190 of the fluid motor 180. The portion 188 further includes a pivot pin 192 which supports the trigger finger arrangement 168 for limited angular motion relative to the stop bar 166. A light torsion spring 194 normally biases the upper end of the trigger finger arrangement 168 away from the stop bar 166 causing the lower portion of the trigger finger arrangement 168 below its pivot 192 to shift away from the operating arm 178 of the limit switch 176. When the upper portion of the trigger finger arrangement 168 is shifted angularly toward the stop bar 166 by the movement of an article to be wrapped thereagainst, the lower portion of the trigger finger arrange-ment shifts the operating arm 178 in a counterclockwise direction (FIG. 11) to close the contacts of the limit switch 176. Retraction of the piston rod 190 of the motor 188 serves to withdraw the stop bar 166 downwardly as guided by the support portion 184. Down-ward shifting of the stop bar 166 and its associated finger 168 allows return of the finger to its outward position as biased by the spring 194 when the finger is retracted below the upper level of the belt conveyor. Also, this downward motion allows return of the operating arm 178 to the position where the contacts of the limit switch 176 are again normally open.

Supported by the framework 24 in predetermined location relative to the above described conveyor means are sealing means for attaching together layers of wrapping material to form packages. Such sealing means may comprise a wide variety of arrangements such as the above referred to transverse sealing arrangement 34 and longitudinal sealing arrangements 36 and 38. The transverse sealing arrangement comprises a lower transverse bar arrangement 208 and an upper transverse bar arrangement 202. The lower bar 280 is supported for vertical reciprocatory motion on a cross bar 204 conneoted at its central portion as at 286 with the upper or outer end of the piston rod 288 of a fluid motor 210. The opposite end of the rod 208 extends downwardly through the lower extremity of the cylinder of the motor 210 and includes a stop arrangement 212 designed to shift vertically between an upper adjustable limit stop 214 and a lower adjustable limit stop 216. The motor 218 is supported in depending fashion beneath a trough shaped member 218 supported on the framework 24. The cross bar 204 is guided for vertical travel in trackways 226 on opposite lateral sides of the machine. Additionally, the cross bar 204 at either lateral extremity thereof includes an upstanding limit switch trip rod 222.

The upper transverse bar arrangement 282 is likewise supported for vertical reciprocation in the guide tracks 220 by means of a cross bar 224 centrally secured as at 226 to the piston rod 228 of a piston cylinder motor 230. The upper end of the piston rod 228 extends outwardly of the cylinder of the motor 238 and reciprocates within an apertured cylindrical housing 232 which includes a stop pin 234 to limit upward travel of the upper bar 202. Downward reciprocation of the upper transverse bar arrangement 202 is determined by the presence of the lower transverse bar arrangement 200, as explained in more detail below. An inverted trough shaped frame portion 236 secured to the framework 24 supports the upper fluid motor 230, as well as a transverse guide roller 238 and a limit switch 248, the purposes of which are also explained below. Finally, the upper cross bar 224 supports a pair of limit switches 242 having depending operating stems 244 positioned to come into abutting relationship with the rods 222 associated with the lower cross bar 204 when the fluid motors 210 and 236 bring the lower and upper transverse seal bars 200 and 202 into contact.

The longitudinal sealing arrangements 36 and 38 are mirror images of each other, and a description of one will thus suflice as a description of both. Each longitudinal sealing arrangement includes lower longitudinal scaling bar 246 and an upper sealing bar 248 generally similar to the lower and upper sealing bars 260, 262 of the transverse sealing arrangement. As best seen in FIGS. 7 and 8, the lower longitudinal sealing bars 246 are supported on a vertically reciprocable support 250 having rollers 252 guided for vertical reciprocation in opposed tracks 254. The tracks 254 are secured to laterally adjustable tower arrangements 256. The vertically reciprocable support 258 is secured to the upper end of a piston rod associated with a fluid motor 258 secured to the laterally adjustable tower 256. An adjustable limit stop block 260 mounted for vertical sliding motion in the tower 256 may be adjusted by a rotary type screw 262 turned by bevel gears 264 in response to operation of a manual crank arrangement 266. An abutment pin 268 associated with the vertically reciprocable support 258 engages a pad 270 on the adjustable stop 260 to define the upper limit of travel of the lower longitudinal seal bar 246. Additionally, a pair of abutment rods 272 is associated with the vertically reciprocable block 250 for the purpose of tripping limit switches, described below.

The upper longitudinal seal bar 248 is pivotally secured at 274 to a vertically reciprocatory support memher 276. The support member 276 also includes rollers 278 riding in the vertical tracks 254 on the tower 256. The support 276 is secured at 280 to the lower or outer end of the piston rod of a fluid motor 282 which is secured to the upper portion of the tower 256. The piston rod of the fluid motor 282 also extends outwardly of the upper extremity of the cylinder of the fluid motor for vertical motion within an apertured cylindrical housing 284. Limit pins 286 associated with the housing 284 determine the upward limit of travel of the upper longitudinal sealing bar 248. The lower limit of travel of the upper longitudinal sealing bar is determined by the upper limit of travel of the lower longitudinal sealing bar. A pair of limit switches 288 located on the support 276 each include a downwardly depending operating foot 220 in vertical alignment with the trip rods 272 which are associated with the lower support 250.

Each of the tower arrangements 256 of the longitudinal sealing arrangements 36 and 38 is mounted for lateral adjustment toward and from the predetermined path of travel of articles through the machine. Such adjustment is guided by transverse track arrangements 292. The transverse location of the towers 256 is determined by a rotary cross shaft 294 which includes a manual crank arrangement 296 at each end and which further includes left-hand and right-hand threaded portions each surrounded by traveling nuts 298 of the ap propriate hand secured to the towers 256 of the longitudinal seal arrangements 36 and 38. Thus, it will be clear that rotation of the manual crank arrangement 296 at either side of the machine serves to impart concurrently inward or concurrently outward lateral adjustment motion of the two tower arrangements to properly position the lower and upper longitudinal seal bars 246 and 248, respectively, relative to the particular width of article which is to be wrapped by the machine of this invention.

The electrical circuitry mentioned above is designed in conventional fashion to produce the following results. The limit switch 164 associated with the trip device 144 of the first belt conveyor 42 is connected to control fluid flow to the motor 180 associated with the stop bar 166 of the second belt conveyor 44 to raise this stop bar to its upward position. The limit switch 174 operated by engagement of an article to be wrapped with the trigger finger 168 associated with the stop bar 166 is electrically connected to disengage the clutches 106 and 116 as well as to apply the brakes 114 and associated, respectively, with the drive shafts 48 and 50 of the first and second belt conveyors 42 and 44 to stop operation thereof. The limit switch 176 is also electrically connected to control fluid flow to the fluid motor 230 to commence downward vertical reciprocation of the upper transverse sealing bar 162 as well as to control flow of fluid to the fluid motor 210 to commence upward vertical reciprocation of the lower transverse sealing bar 200. When the upper and lower transverse sealing bars are practically in contact with one another, the lower bar 280 having already reached its upper limit of travel as determined by the adjustable stop 214, one of the limit switches 242 engages its trip rod 222. This limit switch starts a timer which determines the dwell of the two transverse sealing bars in their closed condition, and this limit switch also assumes control of fluid flow to the motor to shift the stop bar 166 and its associated trigger 'finger arrangement 168 downwardly between the individual conveyor uni-ts of the second belt conveyor 44. The above mentioned timer assumes control of the fluid motors 210 and 230 to separate the transverse sealing bars after a predetermined dwell which may range from a fraction of a second to three seconds: or more depending upon the nature of the wrapping material to be sealed. As the sealing bars separate, the other of the limit switches 242 disengages 'from contact with its associated trip rod 222 to disengage the brakes 164 and 130 and to engage the clutches 106 and 116 to again impart rotary motion to the drive shafts 48 and 50 of the first and second belt conveyors 42 and 44, respectively.

Similarly, as an article to be wrapped engages the other trip device 144 associated with the third belt conveyor 46, the limit switch 164 associated therewith disengages the clutch 134 and engages the brake 138 associated with the drive shaft 52 for the third belt conveyor. Additionally, this limit switch 164 controls fluid flow to. the upper fluid motors 282 and the lower fluid motors 258 associated with each of the longitudinal sealing arrangements 36 and 38 to commerce vertical reciprocation of the sealing bars toward each other. When the upper longitudinal sealing bar 248 is practically in contact with the lower sealing bar 246, which has been quickly shifted to its upward limit of travel as determined by block 260, the operating feet 290 of the limit switches 288 contact their respective trip rods 272. The first of these limit switches 288 starts second and third timers, also not shown, one for each of the longitudinal side sealing arrangements to govern the dwell of the seal bars in contact with each other. After the second and third timers induce separating motion of the longitudinal sealing bars, the second of the limit switches 288 disengages from contact with its associated trip rod 272. When the second limit switches 283 for each side have been disengaged from their trip rods 272, resulting disengagement of the brake 138 and engagement of the clutch 134 again imparts rotary drive motion to the shaft 52 for the third belt conveyor 46 to convey wrapped articles out of the exit end 23 of the machine.

The upper and lower sealing bars for each of the three sealing arrangements described above may include essentially identical heat sealing and severing units, and a description of one pair of such units will serve as a description of each. Referring in particular to FIGS. 16 and 17, each lower sealing bar may include a transverse reaction support 300 having a central elongated resilient pad arrangement 302. Additionally, a passage 304 for cooling fluid 306 may be provided to prevent the sealing bar from attaining unduly high temperatures through repeated operations. Finally, the lower sealing bar arrangement may include a pair of elongated holding surfaces 308 arranged essentially parallel to one another, one on each side of the central resilient surface 302.

The upper bar arrangement 310 may include a central elongated blade arrangement 312 having a rounded abutment edge 314 adapted to contact the resilient reaction surface 302 of the lower sealing arrangement. Heating elements 316 associated with the blade arrangement 312 are adapted to elevate the temperature thereof to a suitable range for sealing and severing thermoplastic Wrapping material. The blade arrangement 312 is rigidly secured as at 318 on the upper sealing bar arrangement.

A pair of holding surfaces 320 arranged generally parallel to one another on opposite sides of the blade arrangement may include adjacent cooling fluid passages, and are spaced to contact the holding surfaces 308 associated with the lower sealing bar arrangement 300. The holding surfaces 320 are mounted for limited lost motion reciprocation relative to the blade arrangement 312 on the sealing bar 310. Suitable compression coil springs 322 normally maintain the surfaces 320 outwardly of the blade 312 as seen in FIG. 16. In this position, as the upper and lower bars first come into contact, the lower holding surfaces 308 and the upper holding surfaces 320 clamp two layers of wrapping material tightly across the slightly raised reaction surface 302. Thereafter, as best seen in FIG. 17, continued relative motion of the upper and lower sealing bar arrangements toward one another serves to take up the lost motion connection with a resultant compression of springs 322.

As the lost motion connection is taken up, it can be seen that the edge 314 of the blade arrangement 312 contacts the two layers of wrapping material stretched across the surface 302. Since the blade arrangement is heated to a predetermined range, the thermo lastic wrapping material is fused at the point of contact with the heated blade whereby the two layers of material are sealed together on each side of the blade, and the blade melts or burns its way through the layer of the wrapping material into direct contact with the surface 302. Accordingly, it is clear that such an arrangement effectively seals and severs plural layers of wrapping material in an amount of time measured in seconds or fractions thereof. Thereafter, as the sealing bar arrangements are retracted, the compression springs 322 again position the holding surfaces 320 to the outer limits of their lost motion connection which insures that thermoplastic material will not adhere to the blade 312, while the cooling fluid 306 in the passage 304 returns the temperature of the lower surfaces 308 and 302 to their normal range whereby they will not adversely affect wrapping material passing closely thereover until the upper sealing bar arrangement descends.

Positioned on the frame 24 longitudinally adjacent and laterally outwardly of each of the opposed lower longitudinal seal bar arrangements 2% is located a suction trough 324. Each elongated suction trough is connected by conduit means 326 with a suction generating compressor arrangement 328 which in turn is connected to remove waste wrapping material longitudinally severed from the sides of wrapped articles and convey such scraps to a remote disposal source through appropriate takeaway conduit means 330.

The first supply station 30 for wrapping material is located on the framework 24 vertically above the first belt conveyor 42. This station comprises a pair of parallel roller supports 332 and 334 arranged in a horizontal plane transversely of the machine 10. As can be seen from the drawings, a roll 336 of wrapping material is supported on the rolls 332 and 334 for unrolling motion, and is horizontally positioned relative thereto by axially adjustable cone boss members 338.

A pair of arm members 340 are pivoted about the axis of the support roller 334, and they include guide rollers 342 located on an axially extending shaft journaled in the outer end of the arms 340. The arms are normally biased by a spring 344 to maintain the guide rollers 342 in contact with the surface of the roll 336 as the diameter thereof diminishes. Located between the arms 340, at a midpoint thereon, is a static eliminator bar 346 spaced a small predetermined distance from the surface of the roll 336 to minimize static electricity inherently built up in such rolls as they are unrolled.

A second pair of swinging arms 348 are pivotally mounted about the axis of the support roller 334. These arms each include a guide roller 350 mounted on an axis 352 located at the outer swinging end of the arms 348. At the mid-portions of the arms 343, a motion transmitting gear 354 is journaled to transmit rotary motion from a gear 356 cooperatively associated with the support roller 334 and to a gear 358 cooperatively connected to drive the guide roller 350. An individual drive unit comprising a motor 360 operating through a speed reduction gear unit 362 is connected by a suitable chain or belting arrangement 364 to impart rotary drive motion to the support roller 334 and hence to the guide roller 350. Since the roll of wrapping material 336 is positioned on the support rollers 334 and 332, it will be clear that power driven rotation of the rollers 334 and 350 serves to generate unrolling motion to feed wrapping material from the roll at a constant speed regardless of the diameter of the roll of material. The unrolled strand 366 of wrapping material, as best seen in FIGS. 6 and 15, is trained from the power driven unrolling support 334 about the guide roller 350, and then beneath a stationary threading roller 368.

A linkage arrangement 370 pivotally connected with the outer end of the sensing arm 348 is pivotally connected at its other end with a radius arm 372 integrally associated with a transverse adjusting shaft 374. A second radius arm 376 also integrally connected with the shaft 374 thereof depends essentially vertically downwardly therefrom to normally ride against an eccentric cam arrangement 378.

The cam arrangement 378 is connected to be rotated by a manual adjusting knob 380 to impart limited angular motion to the shaft 374. As seen in FIG. 15, clockwise rotation of the shaft 374 through a few degrees serves, through the connection 370, to elevate the pivoted arms 348 so that the guide roller 350 about which the unrolled strand of wrapping material is trained will be elevated slightly.

Vertically beneath the guide roller 350 is located a printing roller 382 journaled at opposite ends between a pair of support members 384 for rotation about a horizontal axis extending transversely of the machine. When the adjusting knob 380 permits lowering of the guide roller 350, the unrolling strand of wrapping material 366 is brought into contact with the print roller 382, and when the adjusting knob 380 elevates the guide roller 350, the unrolling strand of wrapping material will not engage the printing roller. Thus, by means of a single manual adjustment, the wrapping material may be printed upon or not as desired depending upon the nature of the article to be wrapped.

The side supports 384 for the printing roller 382 are positioned by means of a shaft 386 in members 388 which are horizontally slideable in the framework 24 of the machine. Locking elements 390 connectable between the members 388 and the frame 24 of the machine serve to retain the printing elements in proper positional relationship in the machine. Simply by loosening the manual members 390, however, the entire printing arrangement may be shifted outwardly of the frame of the machine to facilitate repalcement, filling, repair or other such operations inherently necessary with such printing mechanism.

As noted above, the unrolled strand 366 of wrapping material is trained about the fixed threading roller 368. Thereafter, the strand, as best seen in FIG. 6, is threaded upwardly about a dance arm roller 392 and thereafter downwardly around t 13 above mentioned fixed guide roller 238. Finally, a vertically adjustable guide bar 384 positions the unrolled strand of wrapping material 366 at the desired height above the conveyor means 40 depending upon the height dimensions of articles to be wrapped. The roller 394 is vertically adjustable along a rack arrangement 396 by means of a pinion, not shown, which may be manually operated by means of a lockable knob 398.

The dance arm roller 392 is supported at its opposite ends by a pair of parallel dance arms 400 secured at their other ends on a transversely extending shaft 402 trunnioned in the frame 24 of the machine. The arms 400 are appropriately counterbalanced so that they will swing normally to a position where the bar 392 is elevated above the pivot shaft 402. The counterbalancing, however, is designed so that when the strand 366 of wrapping material below the vertically adjustable guide roller 394 is subjected to longitudinal motion under the influence of an article to be wrapped, the strand 366 of wrapping material will pull on the arms 400 and rotate them downwardly.

The shaft 402 also includes a rotary earn 404 positioned to actuate the above mentioned limit switch 240 secured to the trough shaped support 236. The limit switch 240 is connected to control operation of the drive motor 360 which operates the wrapping material unrolling bar 334. Thus, when the arms 400 are in the normal upward location, the cam 404 permits the normally open electrical contacts of the limit switch 240 to maintain the drive motor 360 inoperative; when the strand of wrapping material 366 pulls the arms 400 downwardly, however, the cam 404 closes the electrical contacts of the switch 240 and renders the drive motor 360 operative to unroll the material from the roll 366 at a constant surface speed until longitudinal pulling on the film ceases and permits wrapping material unrolled thereafter to allow consequent elevating of the arms 400 until the drive motor 360 is again stopped.

The second film unrolling station 32 is located vertically beneath the first belt conveyor 42. The station 32 is similar to the station 30 in many respects, and includes a pair of roll support rollers 408 and 410. The roller 410 is powered by a motivator such as an electric motor 412 operating through a speed reduction gear unit 414 and a suitable chain or belting arrangement 416. The roll supporting roller 408 includes a pair of axially adjustable cone bosses 418 which properly position a second roll of wrapping material 420 axially on the rollers 408 and 410.

The lower film unit including the rollers 408, 410 and the power source 412 are removably mounted on a framework 422 which is slidably supported at 424 in the main framework 24 of the machine 10. The framework 422 is shiftable laterally of the machine to facilitate unloading of empty cores and loading of fresh rolls 420 of wrapping material to the rollers 408 and 410.

A pair of arms 426 are pivotally mounted on the axis of the roller 410 and include a roll following bar 428 connected between their free or outer ends. The mid-portions of the arms 426 support a static electricity eliminator 430 in the same manner as the one associated with the upper wrapping material unrolling station.

Also, as in the upper wrapping material unrolling station, a fixed guide roll 432 secured at opposite ends in ear portions 434 of the shiftable frame 422 position the unrolled strand 436 of wrapping material for threading about a dance arm roller 438 secured between the outer ends of a pair of dance arms 440. The dance arms 440 are mounted on a pivot shaft 422 trunnioned in appropriate pillow blocks 144 secured-to the framework 24 of the machine. A rotary cam 446 is positioned on the shaft 422 to control actuation of a limit switch 448 which in turn is electrically connected to control the drive motor 412 for power unrolling wrapping material from the lower roll 420. After passing around the dance arm roller 438, the unrolled strand 436 of film is directed upwardly about suitable fixed threading bars to a location above the upper surface of the conveyor means 40 where such strand of wrapping material is sealed as at 450 with the strand 366 of wrapping material from the upper roll 336.

To permit upward passage of the strand. 436 of wrapping material, the first conveyor means 42 and the second conveyor means 44 are positioned in end-to-end alignment with their adjacent ends being suificiently spaced to permit passage of film as well as to permit positioning of the lower transverse seal bar arrangement 200 therebetween, but are spaced sufficiently closely that articles such as molded pulp trays 14 may be conveyed in an essentially continuous fashion from the first conveyor means 42 across the transverse seal bar 200, when it is vertically positioned at the appropriate level, and then on to the second conveyor means 44.

In operation, the above described machine operates continuously through cycles initiated by the presence of articles to be wrapped. The description below will follow the path of an article to be wrapped as it is transported through the machine. Initially, a tray 14 made of material such as molded pulp are dispensed seriatim and then filled with produce at stations 18. A roll 336 of wrapping material is placed on the power driven support rollers at the upper wrapping material feed station 30, and another roll 420 of Wrapping material is placed on the power driven support rollers at the lower wrapping material feeding station 32. Wrapping material. from each of these rolls is threaded as described above about the appropriate guide rollers or bars to a location where their ends meet between and slightly above the adjacent ends of the first conveyor means 42 and the second conveyor means 44. The ends are sealed together as at 450 in a manner described below to form a sheet of wrapping material positioned transverse to the longitudinal path determined by the conveyor means 40 which articles to be wrapped follow as they are transported through the machine. With the parts in this position, and with the three upper sealing bar arrangements in their elevated position and with the three lower sealing bar arrangements in their lower position, the machine of this invention is ready to begin operation.

First, an article such as a tray 14 filled with produce, such as the twelve generally spherical oranges or other fruit illustrated, is transported by the first conveyor means 42 from the entrance end 26 of the machine toward the transversely positioned sheet of wrapping material. As the article passes over the trip device 144 which extends upwardly between the individual conveyor units of the first belt conveyor 42, the above outlined electrical circuitry causes elevation of the stop bar 166 between the individual conveyor units of the second belt conveyor 44. Continued progress of the article on the first belt conveyor 42 brings the leading edge of the article into contact with the midportion of the transversely positioned sheet of wrapping material, approximately at the zone where the upper strand 366 and the lower strand 436 are sealed together as at 450. The moving article causes longitudinal motion of the mid-portion of the sheet of wrapping material with a consequential lowering of the upper dance arm bar 392 and raising of the lower dance arm bar 438. Rotation of the upper and lower pairs of dance arms about their pivot shafts causes their associated rotary cams to close the electrical contacts of the upper and lower limit switches 240 and 248, respectively. These limit switches in turn actuate the upper and lower film motors 360 and 412, respectively, to feed the upper and lower unrolling strands of wrapping material laterally toward the predetermined path of the article being wrapped at a constant speed. Such feeding of wrapping material is taken up as the article pulls the upper and lower strands thereof along with it as it crosses the lower transverse sealing bar arrangement 200 and rides on to the second belt conveyor 44.

As the trailing edge of the article passes the vertical plane of the transverse sealing bar arrangements, the leading edge thereof engages the longitudinally positional trigger finger arrangement 168 associated with the stop bar 166. Shifting of the trigger finger arrangement 168 against the upper portion of the stop bar 166 actuates the limit switch 176 to interrupt operation of the belt conveyors 42 and 44 through their respective clutch arrangements 106 and 116 and their respective brake arrangements 114 and 130. It will be appreciated that, as the articles forward longitudinal motion is arrested by stopping of the second belt conveyor 44, the upper and lower film feeding motors will continue to unroll film from the rolls 336 and 420, respectively, until the dance bar arms 392 and 338, respectively, have returned to their normal position swung away from the predetermined article path until their respective rotary cams permit stopping of the power driven unrolling means. Additionally, the limit switch 176 actuates the fluid motors 210 and 230 for. the lower and upper transverse sealing bars 200' and 202, respectively. The lower transverse seal bar 200 is elevated a short distance as controlled by the limit stop 214 until the upper elongated resilient reaction surface thereof is positioned at the desired height where the subsequent transverse seal 450 is to be effected adjacent the trailing surface of the article being wrapped.

Continued downward motion of the upper transverse seal bar 202 causes the limit switches 242 to engage their respective stop rods 222. One of these limit switches starts operation of a first timing device, not shown, which thereafter controls the downward dwell of the upper sealing bar as Well as controlling fluid to the fluid motor 180 to lower the stop bar 166 and its associated trigger finger arrangement 168 below the level of the conveyor means 40 and out of the path of the article being wrapped. The final increment of downward motion of the upper seal bar 202 brings it into contact with the lower seal bar 200 in the manner described above in connection with FIGS.

16 and 17 to effect a transverse seal behind the article being wrapped. This sealing operation simultaneously severs the two sealed layers of wrapping material to provide a laterally oriented tube of wrapping material around the article as well as to form a fresh sheet of transversely positioned wrapping material ready to be engaged by the next article to be wrapped.

The dwell determined by the first timing device for effecting the simultaneous sealing and severing operation will vary depending upon the thickness and composition of the particular thermoplastic wrapping material being used. At the end of this dwell, the timing device controls the upper and lower fluid motors 230 and 210, respectively, to return the upper and lower sealing bars to their rest positions outwardly of the predetermined article path. Movement of the upper sealing bar causes the other limit switch 242 to disengage with its trip rod 222, and this limit switch 242 starts operation of the first and second belt conveyors 42 and 44 through their respective clutch and brake arrangements.

At this point, it will be appreciated that the article encased in a tube of wrapping material may be conveyed directly to a shrink tunnel to provide an open end package. To this end, the longitudinal seal bar arrangements are tie-activated and rolls of wrapping material of appropriate width to correspond with the lateral or width dimensions of the articles to be wrapped are employed.

However, the machine of this invention is designed to provide a complete peripheral seal if desired. To this end, the second belt conveyor, upon being re-activated, conveys the article encased in an open ended tube of wrapping material to the third belt conveyor 46. As the article depresses the trip device 144 associated with the third belt conveyor, the limit switch 164 associated with the trip device interrupts operation of the third belt conveyor 46 by disengaging its clutch 134. In the drawings, the machine is illustrated with the brake arrangement 138 permanently de-activated so that the belt conveyor 46 may coast to a stop carrying the article past the trip device 144 and locating it properly realtive to the longitudinal sealing arrangements. The limit switch 164 associated with the trip device 144 also controls the upper and lower fluid motors 282 and 258, respectively, on each side of the machine for lowering the upper longitudinal seal bars 248 and raising the lower longitudinal seal bars 246. As with the transverse sealing arrangement, the individual pair of lower seal bars 246 are elevated until they are at the proper sealing height relative to the article to be wrapped as determined by the stop block 260 associated with each tower 256.

As the upper seal bars 248 approach the lower seal bars, the pair of operating feet 290 for the limit switches 288 engage their respective trip rods 272. One of the limit switches 288 on each side of the machine starts operation of second and third timing devices, not shown. Again, the timers determine the length of the dwell during which the upper and lower seal bars are in contact on each side of the machine, as described in connection with FIGS. 16 and 17, to form longitudinal seals closing the ends of the tube of wrapping material and severing the excess wrapping material from the peripherally sealed package. Immediately upon such severing, the suction device 328 withdraws the excess trimmed-oft wrapping material from the packaging zone.

As the second and third timing devices induce upward motion of the upper sealing bar and downward motion of the lower sealing bar on each side of the machine, the second limit switches 288 on each side are actuated to control in series the reactivation of the third belt conveyor 46. The third belt conveyor thereupon transports the article peripherally sealed in wrapping material to the conveyor 20 beyond the exit end 28 of the wrapping machine 10, which conveyor 20 thereafter may transport the package through a heating chamber 22 to heat shrink the wrapping material about the article to provide a compact and sturdy merchandizing unit.

While the above described embodiment constitutes the preferred mode of practicing this invention, other embodiments and equivalents may be resorted to within the scope of the actual invention, which is claimed as follows.

What is claimed is:

1. A wrapping machine comprising in combination a wrapping "station, conveyor means connected to transport articles to be wrapped along a predetermined longitudinal path past the wrapping station, the wrapping station including sheets of flexible wrapping material positioned transversely across the predetermined path whereby the mid portions of the sheets will be engaged by articles transported by the conveyor means, the conveyor means including first and second longitudinally aligned belt conveyors arranged with their adjacent ends spaced sufliciently closely to transport article-s thcreacross in a continuous fashion but spaced sufliciently apart to permit transverse positioning of the sheets of flexible wrapping material there-between, means connected to control the first and second belt conveyors for intermittent operation to transport articles to be wrapped with a step-by-step motion along the predetermined path, the control means including a stop bar mounted for shifting motion between operative and inoperative positions, the bar being extended in the operative position into the predetermined path to arrest motion of articles on the conveyors and the bar being retracted in the inoperative position from the predetermined path to permit passage of articles on the conveyors, power driven means at the wrapping station located on opposite sides of the predetermined path to feed wrapping material laterally toward articles to be wrapped at a predetermined rate coordinated with the rate of articles transported by the conveyor means whereby as articles engage the mid-portions of the transversely positioned sheets of wrapping material and move the midportions longitudinally the sheets are arranged intwo layers on opposite sides of articles, and sealing means connected to attach the two layers of wrapping material together adjacent the articles to form packages which comprise articles wrapped in flexible material. 2. A wrapping machine as in claim 1 wherein the stop bar includes a trigger finger arrangement adapted to be engaged by articles on the belt conveyors when the stop bar is in the operative position and cause stopping of the belt conveyors.

3. A wrapping machine as in claim 1 wherein a trip device is positioned adjacent the predetermined path at a location preceding the stop bar and in a manner wherein articles engage the trip device and cause shifting of the stop bar from the inoperative to the operative position.

4. A wrapping machine as in claim 1 wherein the sealing means includes a first sealing means for attaching the two layers together in a transverse direction to form tubes of wrapping material surrounding articles as well as second sealing means connected to attach the two layers together in longitudinal directions on opposite sides of the articles to close the ends of the tubes of wrapping material.

5. A wrapping machine as in claim 4 wherein the first sealing means and the second sealing means each include bar arrangements mounted for shifting motion toward and from each other, one of which includes an elongated resilient reaction surface and the other of which includes an elongated heated blade arrangement adapted to contact the resilient surface.

6. A wrapping machine as in claim 5 wherein the first sealing means and the second sealing means each include adjustable limit means for controlling the location of the bar arrangements thereof when the heated blade arrangement contacts the resilient reaction surface.

7. A wrapping machine as in claim 5 wherein the bar arrangements of the second sealing means are mounted for lateral adjustment toward and from the predetermined 14 path to accommodate wrapping of articles of varying widths.

8. A wrapping machine as in claim 5 wherein each bar arrangement of each sealing means further includes a pair of elongated holding surfaces essentially parallel to each other and spaced on opposite sides of the elongated resilient surface and the elongated blade arrangement, respectively.

9. A wrapping machine as in claim 8 wherein the pair of holding surfaces on at least one of the bar arrangements is mounted for shifting motion relative to the bar arrangement in the direction of to-and-fro motion of the bar arrangement.

10. A wrapping machine as in claim 1 wherein the sealing means includes means for attaching the two layers together to form a seal which laterally surrounds the articles to form packages which comprise articles completely enclosed in flexible material.

11. A wrapping machine as in claim 10 wherein the sealing means includes an elongated heated blade arrangement mounted for shifting motion toward and from the predetermined path.

12. A wrapping machine as in claim 11 wherein the sealing means further includes a pair of elongated wrapping material holding surfaces essentially parallel to each other and spaced on opposite sides of the elongated heated blade arrangement.

13. A wrapping machine comprising in combination a wrapping station, conveyor means connected to transport articles to be wrapped along a predetermined longitudinal path past the wrapping station, the wrapping station including sheets of flexible wrapping material positioned transversely across the predetermined path whereby the mid-portions of the sheets will be engaged by articles transported by the conveyor means, the conveyor means including first and second longitudinal aligned belt conveyors arranged with their adjacent ends spaced sulficiently closely to transport articles thcreacross in a con tinuous fashion but spaced sufliciently apart to permit transverse positioning of the sheets of flexible wrapping material therebetween, the first and second belt conveyors each including a plurality of essentially parallel belt units driven from a common drive shaft, the units being adjustably mounted for transverse spacing relative to one another along the common drive shaft and mounted for swinging motion about the common drive shaft whereby individual belt units may be swung out of parallel with other of the belt units to an inoperative position, power driven means at the wrapping station located on opposite sides of the predetermined path to feed wrapping material laterally toward articles to be wrapped at a predetermined rate coordinated with the rate of articles transported by the conveyor means whereby as articles engage the midportions of the transversely positioned sheets of wrapping material and move the mid-portions longitudinally the sheets are arranged in two layers on opposite sides of articles, and sealing means connected to attach the two layers of wrapping material together adjacent the articles to form packages which comprise articles wrapped in flexible material.

14-. A wrapping machine comprising in combination a wrapping station, conveyor means connected to transport articles to be wrapped along a predetermined longitudinal path past the wrapping station, the wrapping station including a first transverse bar arrangement positioned adjacent the predetermined path and a second transverse bar arangement parallel with the first bar arrangement and also positioned adjacent the predetermined path for transversely positioning sheets of flexible wrapping material across the predetermined path whereby the mid-portions of the sheets will be engaged by articles transported by the conveyor means, the first and second bar arrangements being mounted for shifting motion toward and from each other across the predetermined path, power driven means at the wrapping station located on opposite sides of the predetermined path to feed wrapping material laterally toward articles to be wrapped at a predetermined rate coordinated with the rate of articles transported by the conveyor means whereby as articles engage the midportions of the transversely positioned sheets of wrapping materials and move the mid-portions longitudinally the sheets are arranged in two layers on opposite sides of articles, the power driven means including a first roll of wrapping material connected to feed wrapping material to the first transverse bar arrangement and a second roll of wrapping material connected to feed Wrapping material to the second transverse bar arrangement, each roll of wrapping material being mounted for power driven unrolling, means for reducing static electricity which may tend to build up in the rolls as Wrapping material is unrolled, and sealing means connected to attach the two layers of wrapping material together adjacent the articles to form packages which comprise articles wrapped in flexible material.

15. A wrapping machine as in claim 14 wherein the wrapping material comprises a heat shrinkable film.

16. A wrapping machine as in claim 14 wherein means is provided for printing on the wrapping material from at least one of the rolls thereof between the roll and its associated transverse bar arrangement.

17. A wrapping machine as in claim 14 wherein the power driven unrolling means for at least one of the rolls is mounted for shifting motion to-and-from an operative position on the wrapping machine to facilitate loading of fresh rolls of wrapping material thereto.

18. A wrapping machine comprising in combination a Wrapping station, conveyor means connected to transport articles to be wrapped along a predetermined longitudinal path past the wrapping station, the wrapping station including a first transverse bar arrangement positioned adjacent the predetermined path and a second transverse bar arrangement parallel With the first bar arrangement and also positioned adjacent the predetermined path for transversely positioning sheets of flexible wrapping material across the predetermined path whereby the mid-portions of the sheets will be engaged by articles transported by the conveyor means, the first and second bar arrangements being mounted for shifting motion toward and from each other across the predetermined path, power driven means at the wrapping station located on opposite sides of the predetermined path to feed wrapping material laterally toward articles to be wrapped at a predetermined rate coordinated with the rate of articles transported by the conveyor means whereby as articles engage the mid-portions of the transversely positioned sheets of wrapping material and move the mid-portions longitudinally the sheets are arranged in two layers on opposite sides of articles, the power driven means including a first roll of Wrapping material connected to feed wrapping material to the first transverse bar arrangement and a second roll of wrapping material connected to feed wrapping material to the second transverse bar arrangement, means mounting each roll of wrapping material for power driven unrolling comprising means for unrolling wrapping material at a constant surface speed, control means for the power driven unrolling means comprising a drive motor controlled by limit switch means, the limit switch means including a pivoted trigger arm the free outer end of which engages the wrapping material at a point between the roll thereof and the predetermined path in a manner responsive to a small amount of the longitudinal movement of the mid-portions of the transversely positioned sheets by articles to be wrapped, and sealing means connected to attach the two layers of wrapping material together adjacent the articles to form packages which comprise articles Wrapped in flexible material.

19. A wrapping machine comprising in combination a wrapping station, conveyor means connected to transport articles to be wrapped along a predetermined longitudinal path past the wrapping station, the wrapping station including a first transverse bar arrangement positioned adjacent the predetermined path and a second transverse bar arrangement parallel with the first bar arrangement and also positioned adjacent the predetermined path for transversely positioning sheets of flexible Wrapping material across the predetermined path whereby the mid-portions of the sheets will be engaged by articles transported by the conveyor means, power driven means at the wrapping station located on opposite sides of the predetermined path to feed wrapping material laterally toward articles to be wrapped at a predetermined rate coordinated with the rate of articles transported by the conveyor means whereby as articles engage the mid-portions of the transversely positioned sheets of wrapping material and move the mid-portions longitudinally the sheets are arranged in two layers on opposite sides of articles, and sealing means connected to attach the two layers of wrapping material together adjacent the articles to form packages which comprise articles wrapped in flexible material, the sealing means including a laterally extending, resilient reaction surface and a laterally extending action surface having an elongated blade arrangement, one surface located on the first transverse bar arrangement and the other surface located on the second transverse bar arrangement, means connected to elevate the temperature of the blade arrangement, and passages for circulating cooling fluid along the resilient reaction surface.

29. A wrapping machine as in claim 19 wherein the reaction surface and the action surface each include a pair of longitudinally arranged and generally parallel holding surfaces, one on each side thereof, so positioned and arranged as to grip wrapping material therebetween when the blade arrangement comes into contact with the elongated resilient surface.

21. A wrapping machine as in claim 20 wherein the pair of holding surfaces on at least one of the transverse bar arrangements are mounted for motion relative to the bar arrangement in the direction of to-and-fro motion of the bar arrangement.

References Cited by the Examiner UNITED STATES PATENTS 2,411,075 11/1946 Wyrick 226- 2,707,046 4/1955 Corley et al. 198190 2,741,885 4/1956 Allison 53228 XR 2,928,217 3/1960 Case et al 53228 XR 2,931,148 4/1960 Smith 53182 XR 3,075,328 1/1963 Willbrandt 53-131 XR 3,097,462 7/1963 Langdon 53-180 3,158,973 12/1964 Monaghan 53-66 3,191,356 6/1965 Zelnick et a1 53-229 XR FRANK E. BAILEY, Primary Examiner.

S. ABEND, Assistant Examiner. 

1. A WRAPPING MACHINE COMPRISING IN COMBINATION A WRAPPING STATION, CONVEYOR MEANS CONNECTED TO TRANSPORT ARTICLES TO BE WRAPPED ALONG A PREDETERMINED LONGITUDINAL PATH PAST THE WRAPPING STATION, THE WRAPPING STATION INCLUDING SHEETS OF FLEXIBLE WRAPPING MATERIAL POSITIONED TRANSVERSELY ACROSS THE PREDETERMINED PATH WHEREBY THE MID-PORTIONS OF THE SHEETS WILL BE ENGAGED BY ARTICLES TRANSPORTED BY THE CONVEYOR MEANS, THE CONVYOR MEANS INCLUDING FIRST AND SECOND LONGITUDINALLY ALIGNED BELT CONVEYORS ARRANGED WITH THEIR ADJACENT ENDS SPACED SUFFICIENTLY CLOSELY TO TRANSPORT ARTICLES THEREACROSS IN A CONTINUOUS FASHION BUT SPACED SUFFICIENTLY APART TO PERMIT TRANSVERSE POSITIONING OF THE SHEETS OF FLEXIBLE WRAPPING MATERIAL THEREBETWEEN, MEANS CONNECTED TO CONTROL THE FIRST AND SECOND BELT CONVEYORS FOR INTERMITTENT OPERATION TO TRANSPORT ARTICLES TO BE WRAPPED WITH A STEP-BY-STEP MOTION ALONG THE PREDETERMINED PATH, THE CONTROL MEANS INCLUDING A STOP BAR MOUNTED FOR SHIFTING MOTION BETWEEN OPERATIVE AND INOPERATIVE POSITIONS, THE BAR BEING EXTENDED IN THE OPERATIVE POSITION INTO THE PREDETERMINED PATH TO ARREST MOTION OF ARTICLES ON THE CONVEYORS AND THE BAR BEING RETRACTED IN THE OPERATIVE POSITION FROM THE PREDETERMINED PATH TO PERMIT PASSAGE OF ARTICLES ON THE CONVEYORS, POWER DRIVEN MEANS AT THE WRAPPING STATION LOCATED ON OPPOSITE SIDES OF THE PREDETERMINED PATH TO FEED WRAPPING MATERIAL LATERALLY TOWARD ARTICLES TO BE WRAPPED AT A PREDETERMINED RATE COORDINATED WITH THE RATE OF ARTICLES TRANSPORTED BY THE CONVEYOR MEANS WHEREBY AS ARTICLES ENGAGE THE MID-PORTIONS OF THE TRANSVERSELY POSITIONED SHEETS OF WRAPPING MATERIAL AND MOVE THE MIDPORTIONS LONGITUDINALLY THE SHEETS ARE ARRANGED IN TWO LAYERS ON OPPOSITE SIDES OF ARTICLES, AND SEALING MEANS CONNECTED TO ATTACH THE TWO LAYERS OF WRAPPING MATERIAL TOGETHER ADJACENT THE ARTICLES TO FORM PACKAGES WHICH COMPRISE ARTICLES WRAPPED IN FLEXIBLE MATERIAL. 